<!DOCTYPE HTML>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>测试的拖拽功能</title>
    <style type="text/css">
        body,
        div {
            margin: 0;
            paading: 0;
            font-size: 12px;
        }

        body {
            width: 960px;
            margin: 0 auto;
        }

        ul,
        li {
            margin: 0;
            padding: 0;
            list-style: none;
        }

        .clear {
            clear: both;
            width: 1px;
            height: 0px;
            line-height: 0px;
            font-size: 1px;
        }

        .box {
            width: 600px;
            height: auto;
            margin: 25px 0 0 0;
            padding: 5px;
            border: 1px solid #f00;
        }

        .main {
            position: static;
            width: 600px;
            height: 80px;
            margin-bottom: 5px;
            border: 1px solid blue;
            background: #ccc;
        }

        .maindash {
            position: absolute;
            width: 600px;
            height: 80px;
            margin-bottom: 5px;
            border: 1px dashed blue;
            background: #ececec;
            opacity: 0.7;
        }

        .hide {
            width: 600px;
            height: 80px;
            margin-bottom: 5px;
        }

        .dash {
            position: static;
            width: 600px;
            height: 80px;
            margin-bottom: 5px;
            border: 1px dashed #f00;
        }
    </style>
    <script src="https://code.jquery.com/jquery-3.6.1.min.js"
        integrity="sha256-o88AwQnZB+VDvE9tvIXrMQaPlFFSUTR+nldQm1LuPXQ=" crossorigin="anonymous"></script>
    <script type="text/javascript">

        $(document).ready(function () {

            var range = { x: 0, y: 0 };//鼠标元素偏移量
            var lastPos = { x: 0, y: 0, x1: 0, y1: 0 }; //拖拽对象的四个坐标
            var tarPos = { x: 0, y: 0, x1: 0, y1: 0 }; //目标元素对象的坐标初始化

            var theDiv = null, move = false;//拖拽对象 拖拽状态
            var theDivId = 0, theDivHeight = 0, theDivHalf = 0; tarFirstY = 0; //拖拽对象的索引、高度、的初始化。
            var tarDiv = null, tarFirst, tempDiv;  //要插入的目标元素的对象, 临时的虚线对象
            $(".box").on('mousedown touchstart','.main',function () {
                $(this).mousedown(function (event) {
                    //拖拽对象
                    theDiv = $(this);

                    //鼠标元素相对偏移量
                    range.x = event.pageX || (event.originalEvent.targetTouches&&event.originalEvent.targetTouches[0].pageX) - theDiv.offset().left;
                    range.y = event.pageY || (event.originalEvent.targetTouches&&event.originalEvent.targetTouches[0].pageY) - theDiv.offset().top;

                    theDivId = theDiv.index();
                    theDivHeight = theDiv.outerHeight();
                    theDivHalf = theDivHeight / 2;
                    move = true;

                    theDiv.attr("class", "maindash");
                    // 创建新元素 插入拖拽元素之前的位置(虚线框)
                    tempDiv = $("<div class='dash'></div>");
                    tempDiv.insertBefore(theDiv);
                });
            });

            $(document).on('mousemove touchmove',function (event) {

                if (!move) return false;

                lastPos.x = event.pageX || (event.originalEvent.targetTouches&&event.originalEvent.targetTouches[0].pageX) - range.x;
                lastPos.y = event.pageY || (event.originalEvent.targetTouches&&event.originalEvent.targetTouches[0].pageY) - range.y;
                lastPos.y1 = lastPos.y + theDivHeight;

                // 拖拽元素随鼠标移动
                theDiv.css({ left: lastPos.x + 'px', top: lastPos.y + 'px' });
                // 拖拽元素随鼠标移动 查找插入目标元素

                var $main = $('.main'); // 局部变量：按照重新排列过的顺序  再次获取 各个元素的坐标，
                // tempDiv = $(".dash"); //获得临时 虚线框的对象

                $main.each(function () {
                    tarDiv = $(this);
                    tarPos.x = tarDiv.offset().left;
                    tarPos.y = tarDiv.offset().top;
                    tarPos.y1 = tarPos.y + tarDiv.outerHeight() / 2;

                    tarFirst = $main.eq(0); // 获得第一个元素
                    tarFirstY = tarFirst.offset().top + theDivHalf; // 第一个元素对象的中心纵坐标

                    //拖拽对象 移动到第一个位置
                    if (lastPos.y <= tarFirstY) {
                        tempDiv.insertBefore(tarFirst);
                    }
                    //判断要插入目标元素的 坐标后， 直接插入
                    if (lastPos.y >= tarPos.y - theDivHalf && lastPos.y1 >= tarPos.y1) {
                        tempDiv.insertAfter(tarDiv);
                    }

                });

            }).on('mouseup touchend',function (event) {
                if (!tempDiv) { return }
                theDiv.insertBefore(tempDiv);  // 拖拽元素插入到 虚线div的位置上
                theDiv.attr("class", "main"); //恢复对象的初始样式

                $('.dash').remove(); // 删除新建的虚线div
                move = false;
                tempDiv = null
            });
        });


    </script>
</head>

<body>
    <div class="box" id="box">
        <div class="main" id="main0">div1</div>
        <div class="main" id="main1">div2</div>
        <div class="main" id="main2">div3</div>
        <div class="main" id="main3">div4</div>
        <div class="main" id="main4">div5</div>
    </div>
</body>

</html>